title: A dual-modal magnetic nanoparticle probe for preoperative and intraoperative mapping of sentinel lymph nodes by magnetic resonance and near infrared fluorescence imaging.
abstract: The ability to reliably detect sentinel lymph nodes for sentinel lymph node biopsy and lymphadenectomy is important in clinical management of patients with metastatic cancers. However, the traditional sentinel lymph node mapping with visible dyes is limited by the penetration depth of light and fast clearance of the dyes. On the other hand, sentinel lymph node mapping with radionucleotide technique has intrinsically low spatial resolution and does not provide anatomic details in the sentinel lymph node mapping procedure. This work reports the development of a dual modality imaging probe with magnetic resonance and near infrared imaging capabilities for sentinel lymph node mapping using magnetic iron oxide nanoparticles (10 nm core size) conjugated with a near infrared molecule with emission at 830 nm. Accumulation of magnetic iron oxide nanoparticles in sentinel lymph nodes leads to strong T2 weighted magnetic resonance imaging contrast that can be potentially used for preoperative localization of sentinel lymph nodes, while conjugated near infrared molecules provide optical imaging tracking of lymph nodes with a high signal to background ratio. The new magnetic nanoparticle based dual imaging probe exhibits a significant longer lymph node retention time. Near infrared signals from nanoparticle conjugated near infrared dyes last up to 60 min in sentinel lymph node compared to that of 25 min for the free near infrared dyes in a mouse model. Furthermore, axillary lymph nodes, in addition to sentinel lymph nodes, can be also visualized with this probe, given its slow clearance and sufficient sensitivity. Therefore, this new dual modality imaging probe with the tissue penetration and sensitive detection of sentinel lymph nodes can be applied for preoperative survey of lymph nodes with magnetic resonance imaging and allows intraoperative sentinel lymph node mapping using near infrared optical devices.
authors.affiliation: Department of Radiology and Imaging Sciences, Emory University School of Medicine, Atlanta, GA, USA.
authors.forename: Zhengyang
authors.initials: Z
authors.lastname: Zhou
authors.forename: Hongwei
authors.initials: H
authors.lastname: Chen
authors.forename: Malgorzata
authors.initials: M
authors.lastname: Lipowska
authors.forename: Liya
authors.initials: L
authors.lastname: Wang
authors.forename: Qiqi
authors.initials: Q
authors.lastname: Yu
authors.forename: Xiaofeng
authors.initials: X
authors.lastname: Yang
authors.forename: Diana
authors.initials: D
authors.lastname: Tiwari
authors.forename: Lily
authors.initials: L
authors.lastname: Yang
authors.forename: Hui
authors.initials: H
authors.lastname: Mao
mesh_terms: D000818:Animals; D004396:Coloring Agents; D005260:Female; D006801:Humans; D007797:Laminin / Q000737:chemistry; D008207:Lymphatic Metastasis / Q000175:diagnosis*; D008279:Magnetic Resonance Imaging; D058185:Magnetite Nanoparticles / Q000737:chemistry / Q000648:ultrastructure; D008422:Materials Testing; D051379:Mice; D008819:Mice, Nude; D021701:Sentinel Lymph Node Biopsy / Q000379:methods*; D019265:Spectroscopy, Near-Infrared
chemical_list: C107909:Biomatrix preparation; D004396:Coloring Agents; D007797:Laminin; D058185:Magnetite Nanoparticles
keywords: Sentinel lymph node; magnetic resonance imaging; metastasis; nanoparticles; near infrared; optic imaging